Why does June 29 2011 falls on a Wednesday?

It just does. If you look at the days for it in the years running up to it, you can it progresses by one day each year and two days in a leap year:

Friday 29th of June 2001

Saturday 29th of June 2002

Sunday 29th of June 2003

Tuesday 29th of June 2004 (leap year)

Wednesday 29th of June 2005

Thursday 29th of June 2006

Friday 29th of June 2007

Sunday 29th of June 2008 (leap year)

Monday 29th of June 2009

Tuesday 29th of June 2010

Wednesday 29th of June 2011